1. Field of the Invention
The invention relates to a cylinder head of an engine, and more particularly, to a cylinder head of an engine capable of preventing cylindrical parts for lash adjustors holding lash adjustors from being inclined due to a force applied upon opening/closing of intake valves.
2. Description of the Related Art
As shown in FIG. 6, an engine 101 includes a combustion chamber 103 disposed in a cylinder head 102, two intake ports 104 communicating with the combustion chamber 103, two intake valves 106 configured to open and close intake openings 105 of the two intake ports 104, two swing arms 108 rotatably supported by lash adjustors 107, respectively, and configured to drive the intake valves 106, respectively and two fuel injection valves 110 attached to an intake manifold 109 and configured to inject fuel into the two intake ports 104, respectively.
Patent Document 1 discloses a cylinder head of an engine provided with two intake ports communicating with a combustion chamber of the cylinder head, two intake valves configured to open and close intake openings of the intake ports, respectively, and two swing arms supported to lash adjustors and configured to drive the intake valves. Also, Patent Document 2 discloses a cylinder head of an engine provided with fuel injection valves configured to respectively inject fuel into two intake ports communicating with a combustion chamber of the cylinder head.
The cylinder head of an engine disclosed in Patent Document 1 has a structure in which the fuel injection valves are respectively provided at the two intake ports communicating with the combustion chamber and the lash adjustors respectively support the two swing arms. Cylindrical parts for the fuel injection valves, into which the fuel injection valves are inserted are provided along an outer wall of a cam housing. Thereby, it is not necessary to provide recess parts in cylindrical parts for the lash adjustors, into which the lash adjustors disposed in the cam housing are inserted, for avoiding interference with the fuel injection valves, so that rigidity of the cylindrical parts for the lash adjustors are secured.
Patent Document 1: Japanese Patent Application Publication No. 2010-249060A
Patent Document 2: Japanese Patent Application Publication No. 2009-085056A
As shown in FIG. 6, in the cylinder head 102 of the engine 101, cylindrical parts 111 for the lash adjustor into which the lash adjustors 107 are inserted are disposed at positions spaced from a bottom surface 114 of a bottom wall 113 partitioning a valve chamber 112 of the cylinder head 102. When the cylindrical parts 111 for the lash adjustors are connected to a sidewall 115 disposed at an intake-side of the cylinder head 102, a space 117 may be formed between a lower end portion 116 of the cylindrical parts 111 for the lash adjustors and the bottom surface 114 of the valve chamber 112.
In the cylinder head 102 of the engine 101 having the above structure, the cylindrical parts 111 for the lash adjustors are deformed and inclined by a force applied from intake cams at the time of opening/closing of the intake valves 106. Thereby, there is a problem that the sidewall 115 of the cylinder head 102 vibrates to thus generate noise. Also, as the cylindrical parts 111 for the lash adjustors are inclined, there is a problem that a frictional force acting on a contact part between each of the lash adjustors 107 and each of the swing arms 108 increases to lower durability of the lash adjustors 107 or swing arms 108.